TOKYO, May 31. /TASS/. North Korea launched a space rocket on Wednesday, presumably carrying its first spy satellite, triggering a civil defense alert on Japan’s Okinawa Island.

The J-Alert system advised Okinawa residents to take shelter in buildings or under ground.

The Defense Ministry of Japan said a ballistic missile launch was carried out.

In turn, the South Korean military said the launch was presumably carried out in order to deliver a spy satellite to the orbit.

Meanwhile, residents of South Korea's capital Seoul were told to prepare for a possible evacuation, the Yonhap news agency said.